Thin film transistor liquid crystal displays (TFT-LCD) having characteristics of thin thickness, low power consumption, and no radiation, have been developing rapidly in recent years, so that a dominant position in the current market of flat panel display has been occupied. Currently, TFT-LCDs have been applied widely on products of various sizes, almost covering a majority of electronics in information society now. Examples of TFT-LCDs applied on products of larger size are LCD televisions and high-definition digital televisions.
For the LCD televisions, since area of a sub-pixel unit thereof is relatively large, a TFT on an array substrate is required to have a strong driving capability. Conventional pixel structures can not meet the requirements.